Commercial aircraft, such as the Airbus A320 or Boeing 737, are typically constructed from modular components, the size, weight and construction of which are dictated by many considerations, including fuselage dimensions, aesthetic and safety. Many of these requirements are imposed by law or regulation. Aircraft components, such as overhead stowage compartments, seats, lavatories, galleys, lighting systems, etc. are all required to function within strictly confined spaces.
Manufacturers of aircraft are constantly refining interior aircraft designs to achieve more comfort and utility for passengers and crew within carrier-imposed restraints on cost, weight, maintenance down-time, and safety. Commercial passenger aircraft generally include lavatories for use by passengers and crew.
A conventional lavatory has a rectangular footprint, a toilet, and a sink. It usually also has four composite panel walls that may be molded to fit the curvature of the plane, and a ceiling with built in lighting. The lavatory monument is secured to the aircraft via various tie-rods and brackets, and is designed to independently conform to FAA loading standards. Lavatories have been a standard monument on commercial aircraft for decades. Lavatory monuments are typically constructed as a unit and then installed in an aircraft. After use, the conventional lavatory monument is then removed as a unit from the aircraft and replaced.